The Stovebolt Site Forums The Shop Area Engine Shop Update on an Old Topic

As you may recall, I have a 57 Chevy pickup with 235, 3-speed, Fenton headers and dual exhaust with Flowmaster 40's, Offy intake and 2x 2-bbls and other upgrades.

About 2 years ago I had the 235 professionally built. It lasted about 100 miles before the mains and rod bearings spun. The shop claimed the problem was caused by fuel in the oil. The reluctantly rebuilt it. They may have been right; I never could get those carbs right. Last summer I re-installed that engine and still had trouble getting it to run right.

I sent the truck to a speed shop last fall and they worked on it. It ran better, but not right. I decided to sit the winter out. I had taken it out a few times over the winter for a short 'around the block' drive and it still wasn't quite right. I was getting a lot of lifter noise and at operating temp it wouldn't idle.

I let it run awhile yesterday and the lifter noise seemed to subside. I decided it was time for a road trip so I asked my wife to follow me around the 60-mile loop around Indianapolis. (Good move on my part.)

About 5 miles into the trip I noticed the oil pressure dropping and thought I was hearing the lifter noise come back. It's difficult to hear much in that truck (thanks Flowmaster). By the time I had gone 10 miles, the oil pressure had dropped from about 20-30# to about 5# at 60 MPH. I also kept losing power and then it would come back.

My theory is that the shop didn't look at the cam bearings on the second rebuild and they're bad. That's the top end and and oil pressure issue. I believe the loss of power is caused by the carbs flooding.

Oh; when the truck stopped, it would barely turn over. I assume the temp was up a bit (but not hot; in fact I didn't notice any increase in temp during all of this) and the timing may be off a bit. When it cooled a bit, the truck started and ran ok (by its current standard).

It took AAA 4 hours to pick me up and haul the truck to the shop. That's where it was handy to have my wife behind me. At least she had heat in her car.

What are your thoughts? I like the nostalgia of the 235 but it's getting old. I thought those things were bullet proof. Oh; this is a 62 hydraulic lifter engine. I'm running the original 3-speed on the column and have converted to 3.55 open rear-end.

I'd check the oil level on the dipstick to see if its over full? That would be the fastest way to see if your engine was being drowned with gasoline. I'm not doubting your carb issues but I'd be more inclined to think that maybe the engine block needs align boring? Just a couple of thoughts, more guys will have more later I'm sure. The best advise I can offer is take your time finding the cause of the problem. Nothing is bullet proof, but some are tougher than others and your choice here should be a good one, you just need to get all your ducks in a row.
Don

Losing oil pressure at highway speed on a new engine is not a good thing! it sounds like the engine was not cleaned well on the second buildup, and debris circulating with the oil has trashed the rod and main bearings again. I never attempt a partial buildup after any oil-related failure- - - -the engine comes down to a bare block again and all the oil passages get brushed out and pressure washed. Your first clue should have been the lifter noise. The beginning of a debris-related failure usually clogs the one-way valves in the lifters, allowing them to collapse under load.
Jerry

As Don mentioned, first check is the oil dipstick; both to check for overfull and the condition (contamination) of the oil.

It is certainly possible for carburetors to pour in so much fuel that one washes down the rings, and fills the crankcase with fuel; HOWEVER, if this is the case, your wife would have been unable to see you for the black smoke!

My guess would be something else, as mentioned by Jerry.

Jon.

carbking,

I should have listened to you a couple of years ago when we talked about carbs for this thing. I've had nothing but trouble with these Holley/Webers.

They actually seem to be ok right now, but the truck sure isn't.

I agree with Hotrod, The engine should be torn down and throughly cleaned and inspected. If your not doing the work yourself I think you also need to consider changing engine rebuilders.

I've already changed builders. That's why the truck is at a performance shop. This guy builds high-RPM, high-hp engines. Their site is down for maintenance or I'd give you a link. The shop is Automazing. The owner is Dave Himes.

The preliminary diagnosis is that the builder didn't fix the play in the thrust bearing and it took out the mains and rod bearings and the trash from those took out the cam. We're back at square one. 3 builds in less than 200 miles; can it get any better than this?

I had two in under 100 miles. Hang in there.

Have you talked with Stovebolt Engine Co.'s Tom Langdon? Two H-W's are only recommended for a 261, you've got too much cfm for a 235. He recommends 2 - Carter-Webers for a 235. Have you talked this over with the guys at inliners.org ?

Are you running manifold heat?

Yes. I'm running hot water from the block sold by Langdon's.

I don't know why I always mix these two carbs up. They are Carter/Webers. I discussed the engine with Tom when I was upgrading to the 2x intake and again when I was having some vacuum issues after install. I talked to the performance shop last night and they're pretty sure they have the carb issue solved now.

I think I'm going to go with an RV cam and a Tremec 5-speed while I'm at it. Hell; it's only money, right?

Just got off the phone with Automazing. They will rebuild the 235, install a RV cam and convert to Tremec 5-speed. I should be cruising in 3 weeks.